problem: udp doesn't enforce correct usage of bind/connect

solution: enforce that dish and gram can only bind and radio can only
connect

src/socket_base.cpp

@@ -556,9 +556,9 @@ int zmq::socket_base_t::bind (const char *addr_)
         return rc;
     }
 
-    if (protocol == "pgm" || protocol == "epgm" || protocol == "norm" || protocol == "udp") {
+    if (protocol == "pgm" || protocol == "epgm" || protocol == "norm") {
         //  For convenience's sake, bind can be used interchangeable with
-        //  connect for PGM, EPGM, NORM and UDP transports.
+        //  connect for PGM, EPGM, NORM transports.
         EXIT_MUTEX ();
         rc = connect (addr_);
         if (rc != -1)
@@ -566,6 +566,64 @@ int zmq::socket_base_t::bind (const char *addr_)
         return rc;
     }
 
+    if (protocol == "udp") {
+        if (!(options.type == ZMQ_DGRAM || options.type == ZMQ_DISH)) {
+            errno = ENOCOMPATPROTO;
+            EXIT_MUTEX ();
+            return -1;
+        }
+
+        //  Choose the I/O thread to run the session in.
+        io_thread_t *io_thread = choose_io_thread (options.affinity);
+        if (!io_thread) {
+            errno = EMTHREAD;
+            EXIT_MUTEX ();
+            return -1;
+        }
+
+        address_t *paddr = new (std::nothrow) address_t (protocol, address, this->get_ctx ());
+        alloc_assert (paddr);
+
+        paddr->resolved.udp_addr = new (std::nothrow) udp_address_t ();
+        alloc_assert (paddr->resolved.udp_addr);
+        rc = paddr->resolved.udp_addr->resolve (address.c_str(), true);
+        if (rc != 0) {
+            LIBZMQ_DELETE(paddr);
+            EXIT_MUTEX ();
+            return -1;
+        }
+
+        session_base_t *session = session_base_t::create (io_thread, true, this,
+            options, paddr);
+        errno_assert (session);
+
+        pipe_t *newpipe = NULL;
+
+        //  Create a bi-directional pipe.
+        object_t *parents [2] = {this, session};
+        pipe_t *new_pipes [2] = {NULL, NULL};
+
+        int hwms [2] = {options.sndhwm, options.rcvhwm};
+        bool conflates [2] = {false, false};
+        rc = pipepair (parents, new_pipes, hwms, conflates);
+        errno_assert (rc == 0);
+
+        //  Attach local end of the pipe to the socket object.
+        attach_pipe (new_pipes [0], true);
+        newpipe = new_pipes [0];
+
+        //  Attach remote end of the pipe to the session object later on.
+        session->attach_pipe (new_pipes [1]);
+
+        //  Save last endpoint URI
+        paddr->to_string (last_endpoint);
+
+        add_endpoint (addr_, (own_t *) session, newpipe);
+
+        EXIT_MUTEX ();
+        return 0;
+    }
+
     //  Remaining transports require to be run in an I/O thread, so at this
     //  point we'll choose one.
     io_thread_t *io_thread = choose_io_thread (options.affinity);
@@ -881,9 +939,15 @@ int zmq::socket_base_t::connect (const char *addr_)
 #endif
 
 if (protocol  == "udp") {
+    if (options.type != ZMQ_RADIO) {
+        errno = ENOCOMPATPROTO;
+        EXIT_MUTEX ();
+        return -1;
+    }
+
     paddr->resolved.udp_addr = new (std::nothrow) udp_address_t ();
     alloc_assert (paddr->resolved.udp_addr);
-    rc = paddr->resolved.udp_addr->resolve (address.c_str(), (options.type == ZMQ_DISH || options.type == ZMQ_DGRAM));
+    rc = paddr->resolved.udp_addr->resolve (address.c_str(), false);
     if (rc != 0) {
         LIBZMQ_DELETE(paddr);
         EXIT_MUTEX ();
@@ -1284,7 +1348,7 @@ int zmq::socket_base_t::recv (msg_t *msg_, int flags_)
 int zmq::socket_base_t::close ()
 {
     ENTER_MUTEX ();
-    
+
     //  Remove all existing signalers for thread safe sockets
     if (thread_safe)
         ((mailbox_safe_t*)mailbox)->clear_signalers();

src/udp_address.cpp

@@ -55,7 +55,7 @@ zmq::udp_address_t::~udp_address_t ()
 {
 }
 
-int zmq::udp_address_t::resolve (const char *name_, bool receiver_)
+int zmq::udp_address_t::resolve (const char *name_, bool bind_)
 {
     //  Find the ':' at end that separates address from the port number.
     const char *delimiter = strrchr (name_, ':');
@@ -78,8 +78,8 @@ int zmq::udp_address_t::resolve (const char *name_, bool receiver_)
     dest_address.sin_family = AF_INET;
     dest_address.sin_port = htons (port);
 
-    //  Only when the udp is receiver we allow * as the address
-    if (addr_str == "*" && receiver_)
+    //  Only when the udp should bind we allow * as the address
+    if (addr_str == "*" && bind_)
         dest_address.sin_addr.s_addr = htons (INADDR_ANY);
     else
         dest_address.sin_addr.s_addr = inet_addr (addr_str.c_str ());
@@ -106,9 +106,9 @@ int zmq::udp_address_t::resolve (const char *name_, bool receiver_)
         return -1;
     }
 
-    //  If a receiver and not a multicast, the dest address
+    //  If a should bind and not a multicast, the dest address
     //  is actually the bind address
-    if (receiver_ && !is_mutlicast)
+    if (bind_ && !is_mutlicast)
         bind_address = dest_address;
     else {
         bind_address.sin_family = AF_INET;

tests/test_dgram.cpp

@@ -60,7 +60,11 @@ int main (void)
     void *sender = zmq_socket (ctx, ZMQ_DGRAM);
     void *listener = zmq_socket (ctx, ZMQ_DGRAM);
 
-    int rc = zmq_bind (listener, "udp://*:5556");
+    //  Connecting dgram shoudl fail
+    int rc = zmq_connect (listener, "udp://127.0.0.1:5556");
+    assert (rc == -1);
+
+    rc = zmq_bind (listener, "udp://*:5556");
     assert (rc == 0);
 
     rc = zmq_bind (sender, "udp://*:5557");
@@ -68,7 +72,7 @@ int main (void)
 
     str_send_to (sender, "Is someone there ?", "127.0.0.1:5556");
 
-    str_recv_from (listener, &message_string, &address);    
+    str_recv_from (listener, &message_string, &address);
     assert (strcmp(message_string, "Is someone there ?") == 0);
     assert (strcmp(address, "127.0.0.1:5557") == 0);
     free (message_string);

tests/test_udp.cpp

@@ -95,9 +95,17 @@ int main (void)
     void *radio = zmq_socket (ctx, ZMQ_RADIO);
     void *dish = zmq_socket (ctx, ZMQ_DISH);
 
-    int rc = zmq_bind (dish, "udp://*:5556");
+    //  Connecting dish should fail
+    int rc = zmq_connect (dish, "udp://127.0.0.1:5556");
+    assert (rc == -1);
+
+    rc = zmq_bind (dish, "udp://*:5556");
     assert (rc == 0);
 
+    //  Bind radio should fail
+    rc = zmq_bind (radio, "udp://*:5556");
+    assert (rc == -1);
+
     rc = zmq_connect (radio, "udp://127.0.0.1:5556");
     assert (rc == 0);